1. Field of the Invention
The present invention relates to a detonation engine which utilizes the detonation phenomenon accompanying a normal shock wave at the front of a combustion wave.
2. Description of Related Art
As a detonation engine which utilizes the detonation phenomenon, there is known a pulse detonation engine comprising an outlet valve at the exit of the combustion tube (for example, refer to Takayuki Kojima, “Conceptual Study on Application of PDE to Hypersonic Propulsion system”, the proceedings of Symposium on Shock Waves, 2003 Japan, p. 113 to 116 (hereunder, “Document 1”)), and a combined cycle pulse detonation turbine engine comprising a plurality of shock tubes (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2001-355515 (FIG. 1 and FIG. 2) (hereunder, “Document 2”)).
However, in the pulse detonation engine disclosed in Document 1 there is a problem in that: when the outlet valve is closed, the closed valve becomes resistive; the overall engine structure becomes complicated due to providing such an outlet valve; and exhaust due to fuel replenishment, combustion, and expansion waves is performed repeatedly at a cycle of about 10 Hz to 100 Hz, and hence continuous output cannot be obtained.
On the other hand, in the combined cycle-pulse detonation-turbine engine disclosed in Document 2, the structure is such that the valve, being a problem in Document 1, is removed and continuous output can be obtained for the overall engine. However a plurality of shock tubes must be provided, and hence there is still the problem of complicated overall engine structure.